The present invention relates to an automatic document or original feeder usable with image recording machines such as an electrophotographic copying machine, a laser beam printer, a facsimile machine or an ink jet printer. More particularly, the invention relates to an automatic document feeder capable of automatically feeding both sided originals to an image reading station for recording the images of both sides. Further, the invention also relates to an image recording apparatus provided with an automatic document feeder.
Various types of automatic document feeders for automatically feeding an original for duplex image recording are known.
For example, U.S. Pat. Nos. 4,099,150, 4,140,387 and 4,158,500 disclose the feeders of those types. In the devices disclosed therein, both sides of an original can be automatically fed to the image reading station, and the original, after being read, is returned to the original feeding station in the same page order as before the feeding to the reading station so that it is convenient for handling; however, the machines disclosed in U.S. Pat. Nos. 4,099,150 and 4,140,387 require an additional storing portion for stacking in addition to the pre-feeding stacking portion, resulting in bulkiness of the machine and a complicated control of the originals. U.S. Pat. No. 4,158,500 discloses a single stacking portion. However, the original is introduced to a platen of a reading station from one end and discharged from the other end, resulting in a complicated and bulky driving mechanism. Additionally, U.S. patent application Ser. No. 632,214 filed on July 18, 1984 assigned to the assignee of this application proposes an automatic document feeding device. The present invention is a further improvement of the apparatus of this type.